Predicting the long-term use of overlays in children: the Pattern Glare Test

Abstract

Aim: To determine whether the Institute of Optometry Pattern Glare Test (PGT) could be used as a sensitive tool to predict the continued use of coloured overlays for reading in schoolchildren aged 7 to 12 years and to compare its sensitivity with that of the Wilkins Rate of Reading Test (WRRT) and the Developmental Eye Movement (DEM) test. Methods: Twenty-six children referred for a coloured overlay assessment in relation to difficulties with literacy skills were recruited to the study. An assessment took place which included orthoptic examination, coloured overlay assessment, PGT, WRRT and DEM test. The overlay chosen was provided for use at home and at school and followup took place 13-15 weeks later. Overlay usage was then analysed in relation to the scores recorded at the initial visit for PGT, WRRT and DEM test. Results: Nineteen children were still consistently using their overlays at the follow-up visit. No statistically significant difference was found in the PGT score of those children who consistently used overlays (group 1) compared with those who did not (group 2) (unpaired t-test, p = 0.62). The PGT was found to have 53% sensitivity in predicting those children who would consistently use overlays, compared with 79% for the WRRT and 77% for the DEM test. Conclusion: This study did not find the PGT to be a sensitive tool for predicting those children who would consistently use overlays in comparison with the WRRT and the DEM test.